Bug#972936: libgcc-s1 needs Breaks: libgcc1 (<< 1:10)

[Ivo De Decker <ivodd@debian.org>]

# clarify issue in 972936
retitle 972936 removal of libgcc-s1 breaks the whole system
fixed 972936 10.2.0-16
# 
# purely cosmetic, as this specific issue is fixed
severity 964477 serious
thanks

Hi,

On Wed, Mar 03, 2021 at 11:31:07AM +0100, Matthias Klose wrote:
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=964477#69
> now claims this is gone with the removal of gcc-8

It seems there is some confusion between #972936 and #964477, as the bug log
of #972936 contains some info that's only relevant for #964477.


First, bug 972936:

The issue as reported in
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=972936#5 was fixed in gcc-10
10.2.0-16 with the change suggested by Julian in
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=972936#24

"Mark libgcc-sN with XB-Important/Protected: yes. Addresses: #972936"

I can reproduce the original issue when installing libgcc-s1 from bullseye
from snapshot based on this link:

deb [check-valid-until=no] https://snapshot.debian.org/archive/debian/20201012T000000Z/ bullseye main

When installing libgcc-s1 from current bullseye, apt is no longer willing to
remove libgcc-s1 (without 'do as I say').



Now bug 964477:

This bug can be reproduced based on Ryans script:

On a buster system:

apt-get install -y --no-install-recommends gcc-8 libc6-dev libreoffice

Switch the sources.list to a bullseye snapshot from before the removal of
gcc-8 (see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=964477#64)

Then run
apt-get -y dist-upgrade
to get the error.


When trying to upgrade to a current version of bullseye, the issue doesn't
show up, because gcc-8 is no longer there. So it seems this issue was resolved
with the removal of gcc-8 from testing.


I also can confirm that trying to upgrade to a snapshot of bullseye that has
gcc-8 works with the packages from Ryan based on this sources entry:

deb  http://download.opensuse.org/repositories/home:/rpavlik:/bullseye-fix/Debian_Testing/ ./
(which needs
https://salsa.debian.org/rpavlik/gcc-upgrade-testcase/-/blob/main/workaround.asc
to be accepted by apt)

Even though the issue from 964477 is fixed, it's possible that there are
similar issue (not related to gcc-8) we are currently unaware of. So it might
still be useful to reintroduce the transitional packages, as suggested by
David in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=964477#41

Finally, I think 964477 should be marked as serious (even though that's purely
cosmetic now, as the bug is fixed).


Cheers,

Ivo